**Core Concept**
Nitrous oxide is a colorless gas with analgesic and anxiolytic properties, commonly used in medical and dental procedures for its pain-relieving effects. It works by activating the opioid receptors in the brain, leading to a reduction in pain perception.

**Why the Correct Answer is Right**
The correct answer is Sir Humphry Davy who first used Nitrous oxide for the abolition of pain in dental procedures. He discovered the analgesic properties of Nitrous oxide in 1799, and it has since become a widely used anesthetic gas in dentistry. The mechanism of action involves the activation of opioid receptors in the brain, which leads to a reduction in pain perception.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as there is no historical evidence to suggest that this person was involved in the discovery of Nitrous oxide's analgesic properties.
**Option B:** This option is incorrect as this person is not associated with the use of Nitrous oxide in dental procedures.
**Option C:** This option is incorrect as this person is not credited with the discovery of Nitrous oxide's analgesic properties.

**Clinical Pearl / High-Yield Fact**
Nitrous oxide is a safe and effective anxiolytic agent, commonly used in dental procedures. It is often used in combination with other anesthetic agents to provide a safe and pain-free experience for patients.

**Correct Answer: C. Horace Wells**